smf2rmid and rmid2smf are two com­mand line util­i­ties that let you con­vert be­tween SMF (Stan­dard MI­DI File) and RMID (RIFF MI­DI) for­mat. An RMID file is merely a wrapper around a Standard MIDI File; the original file is unmodified.

MidiYodi allows editing, examination, and playback of MIDI files. It contains an explorer which gathers a MIDI information summary from entire file collections and tools to edit and examine events and notes from individual tracks.

au is a little script to make ffmpeg easier to use for common audio manipulations like cutting to a specific number of beats at a set BPM, volume adjustments, joining files together, and converting between file formats or between mono and stereo.

The ALSA MIDI Filter application consists of a main script, named midifilter, and supporting Perl modules, configuration files, and documentation. It runs as an ALSA MIDI client that can receive input from a source (such as a MIDI keyboard connected to the computer), perform various filtering and other functionality based on the type and content of the MIDI input, and send the result to one or more other MIDI clients.

DRM-SEQ is a basic drum machine and sampler. It allows realtime pattern creation with customizable samples and tracks. It has an adjustable BPM, swing factor, time signature, and eight banks for patterns, with intuitive key bindings and save/load capabilities for a live environment.

MPDisco is a Node.js-based music server built to let teams and groups control a single music player together.
Accessing an MPDisco server puts each user, after logging in, in a rotating DJ queue. Each user will be given one hour (by default) to control the playlist and music player.

Hang The DJ is a music server and set of players designed to be your personal DJ. Comprehensive ratings are maintained for each of your songs, and the ratings are used to intelligently and automatically generate music that is just right for the mood you are in.

ApplPi is a stochastic noise machine that creates a soothing background noise for those who can't work in complete silence or need to mask distracting noise. It creates sound similar to any noise machine, but it's more musical and harmonic. Additionally, you can control the frequency (note) of the sound and choose from built-in presets of noise/sound.